ERROR on recovery --> E: failed to mount /data (Invalid argument)

[adelsouza]

Guys, we save my life. tks a lot.

 

[Reymart Tibe]

I know how to fix that...

 

[D Gib]

I had the same problem which started with my phone losing my wallpaper all the time within minutes, then going to a black background and being really slow, & slow to reboot until it finally wouldn't get past the SAMSUNG logo when rebooted, seems it's from corruption of the partitions. Biggest problem was that since USB debuggingg wasn't enabled, I had a hard time connecting to my pc. Was able to with ODIN & proper drivers. Found many bogus or old drivers and roms out there that were useless. This fixed it after flashing a the latest rom for my SCH-T999L rom via ODIN as here https://www.theandroidsoul.com/t999luvuboh1-new-update-for-t-mobile-galaxy-s3-lte-sgh-t999l/, but I still had the bad E:\ partition & it wuld now get to the T-Mobile screen and hang. The below fix that. Seems that the stock recovery doesn't wipe and format all the cache & partitions, TWRP did. All in all, except for some loss of data ( keep most on my extSD card) and Google backup supplied a lot of the rest, including reinstalling many of my apps with their data, it turned out to be a good thing because being rooted and with TWRP I can now customize my old S3 with some newer roms and can use Titanium backup and SuperBackup to their full extent. And my device zooms now compared to what it was before. Evidently there was a lot of leftover garbage from old apps, because I have 9 gigs of free space now & 500mb of system space left.

Note especially that you should not mess with the pit file in ODIN when flashing. Also note that this was especially for a TMobile T999L (different from T999), althought the TWRP & Superuser will work on either TMOBILE Galaxy S3.
1. Install Odin & TWRP as stated here https://www.theandroidsoul.com/how-to-install-twrp-recovery-using-odin/
2.use TWRP to reformat data, cache, & davlich
3. I rooted at the same time (might as well) using ODIN as here https://www.theandroidsoul.com/how-to-flash-supersu-using-twrp-recovery-and-root-any-android-device/

 

[scienti5t]

Same here tried to install custom kernel and got the same thing that you got
I already installed zombie kernel an tried to install savie duos kernel and twrp
I think twrp ****ed it up
**** twrp
CWM IS THE BEST